title: Safety and efficacy of stereotactic body radiotherapy for stage 1 non-small-cell lung cancer in routine clinical practice: a patterns-of-care and outcome analysis.
abstract: BACKGROUND
  To evaluate safety and efficacy of stereotactic body radiotherapy (SBRT) for stage I non-small-cell lung cancer (NSCLC) in a patterns-of-care and patterns-of-outcome analysis.
  
  
  METHODS
  The working group "Extracranial Stereotactic Radiotherapy" of the German Society for Radiation Oncology performed a retrospective multicenter analysis of practice and outcome after SBRT for stage I NSCLC. Sixteen German and Austrian centers with experience in pulmonary SBRT were asked to participate.
  
  
  RESULTS
  Data of 582 patients treated at 13 institutions between 1998 and 2011 were collected; all institutions, except one, were academic hospitals. A time trend to more advanced radiotherapy technologies and escalated irradiation doses was observed, but patient characteristics (age, performance status, pulmonary function) remained stable over time. Interinstitutional variability was substantial in all treatment characteristics but not in patient characteristics. After an average follow-up of 21 months, 3-year freedom from local progression (FFLP) and overall survival (OS) were 79.6% and 47.1%, respectively. The biological effective dose was the most significant factor influencing FFLP and OS: after more than 106 Gy biological effective dose as planning target volume encompassing dose (N = 164), 3-year FFLP and OS were 92.5% and 62.2%, respectively. No evidence of a learning curve or improvement of results with larger SBRT experience and implementation of new radiotherapy technologies was observed.
  
  
  CONCLUSIONS
  SBRT for stage I NSCLC was safe and effective in this multi-institutional, academic environment, despite considerable interinstitutional variability and time trends in SBRT practice. Radiotherapy dose was identified as a major treatment factor influencing local tumor control and OS.
authors.affiliation: Universität Würzburg, Klinik und Poliklinik für Strahlentherapie, Würzburg, Germany. guckenberger_m@klinik.uni-wuerzburg.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Guckenberger
authors.forename: Michael
authors.initials: M
authors.lastname: Allgäuer
authors.forename: Steffen
authors.initials: S
authors.lastname: Appold
authors.forename: Karin
authors.initials: K
authors.lastname: Dieckmann
authors.forename: Iris
authors.initials: I
authors.lastname: Ernst
authors.forename: Ute
authors.initials: U
authors.lastname: Ganswindt
authors.forename: Richard
authors.initials: R
authors.lastname: Holy
authors.forename: Ursula
authors.initials: U
authors.lastname: Nestle
authors.forename: Meinhard
authors.initials: M
authors.lastname: Nevinny-Stickel
authors.forename: Sabine
authors.initials: S
authors.lastname: Semrau
authors.forename: Florian
authors.initials: F
authors.lastname: Sterzing
authors.forename: Andrea
authors.initials: A
authors.lastname: Wittig
authors.forename: Nicolaus
authors.initials: N
authors.lastname: Andratschke
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016634:Radiosurgery / Q000009:adverse effects; D061089:Radiotherapy, Image-Guided; D012189:Retrospective Studies; D016896:Treatment Outcome